Smoke-preventer.



No.-866,510. PATENTED SEPT. 17, 1907.

. B. B. PARKHURST.

SMOKE PREVBNTERQ APPLICATION FILED APB-14.1906.

ms NORRIS PETERS co., WASHING'IUN, n. c

EDWARD B. PARKHURST, OF WOBURN, MASSACHUSETTS.

SMOKE -PRE VE N TER.

Specification of Letters Patent.

Patented Sept. 17, 1907.

Application filed April 14, 1906. Serial No. 311,635.

To all whom it may concern;

Be it known that I, EDWARD B. PARKI-IURsr, a citizen of the United States, residing at Woburn, in the county of Middlesex and Commonwealth of Massachusetts, have invented a certain new and useful Improvement in Smoke-Preventers, of which the following is a specification, reference being had therein to the accompanying drawings.

My invention has for its object the improvement of the smoke preventer of the well-known type, in which air is introduced into the furnace through a suitable pipe by means of a jet of steam. I

The particular object of the improvement is to secure greater efficiency by proper joint action of the parts controlling the supply of steam and air. The device is especially adapted to give equally good results even when in the hands of careless or unintelligent firemen. To this end, my invention provides means for operating the dampers at the exterior of the air inlet pipe, so that the said dampers shall be opened automatically at the time when the steam valve is opened and closed simultaneously with the closing of the steam valve, both valve and dampers being operated by the action of the furnace door.

The device is simple in construction and is adapted to be applied to a variety of different forms of furnaces.

The invention will be understood from the following description, taken together with the accompanying drawings and the novel features thereof will be pointed out and clearly defined in the claims at the close of this specification.

Referring to the drawings,Figure 1 is the front view of a furnace to which my invention is applied. Fig. 2 is a plan view of so much thereof as pertains to the present invention. Fig. 3 is a detail of the part shown at the right of Fig. 2. Fig. 4 is a detail of the part shown at the left of Fig. 2. Fig. 5 is a detail showing the cams on the sliding bar and bracket. The three last mentioned views are on a somewhat enlarged scale for clearness of illustration.

Referring to the drawings the front of the furnace is designated by the numeral 6 and the furnace doors by the numerals 7 and 8 At 9 and 10 are shown the ash-pit doors, and at 11 and 12 the two dampers controlling the supply of air to the two inlet pipes not shown, and at 13 and 14 are indicated the clean-outs for the steam nozzles. In the drawings, I have shown only two smoke preventers, but it will be seen that any desired number may be employed and that the devices embodying the present invention will operate them with equal success.

I have not thought it necessary to show the interior construction of the smoke preventers, or the air inlet pipes, because these devices are well-known to those skilled in the art, and my invention is applicable with equal success to a variety of different constructions of these devices.

The main steam supply pipe is designated 15, the two smoke preventers being supplied through branch pipes 16 and 17. The steam valve 18 which controls the flow of steam to the two preventers is operated by a valve spindle 19, said valve 18 being of such con struction that it will open wide or substantially wide with about a half revolution of the valve spindle. The lower end of the valve spindle 19 is provided with a crank 20 and gear 21, and is supported in hearings in a bracket 22. A pin 23 is provided on the outer arm of the crank 20 and contacts with the furnace door 7, so that when the furnace door is opened, it will cause the crank 20, gear 21, and valve spindle 19 to rotate about their axis. A corresponding crank 231, gear 24, pin 25 and bracket 30 are provided at the left hand side of the furnace and adapted to be operated by the opening of the door 8, but the said crank 231 swings in the reverse direction from the crank 20, because each door is hinged on the side toward the outside of the furnace, and therefore the doors swing in opposite directions. The gears 21 and 24 engage a pair of racks, 251 and 261 respectively, the rack 251 being on the front side of the gear 21, while the rack 261 is behind the gear 24. Both racks 251 and 261 are mounted on a sliding bar 27, which is free to slide in slots 28 and 29 in the brackets 22 and 30. The construction of these parts will be clearly seen from Figs. 3 and 4. The sliding'bar 27 is provided with two slots 31 and 32 for engagement with the two pins 33 and 34 on the two dampers 11 and 12 heretofore referred to. It will thus be seen that if the sliding bar 27 is moved to the right by the action of either of the gears 21 and 24, the first part of its movement will have no effect on the said dampers 11 and 12, because the pins 33 and 34 are free to slide in the slots 31 and 32, but when the I said pins reach the end of the said slots, the dampers will be opened by the remainder of the movement of the sliding bar 27. It will also be seen that opening either door 7 or 8 will cause the valve 18 and dampers 11 and 12 to be simultaneously operated.

In the drawings, I have shown the doors 7 and 8 of the furnace as hinged to swing in opposite directions, and consequently reverse the position of the two racks 251 and 261, so that opening either of the doors will operate the valve and dampers. It is obvious that if it is desired to have the doors open in the same direction, both racks will be either on the front or the back of the gears as the case may be. On the under side of the racks 251 and 261 I provide two cam surfaces 252 and 253 as seen in Fig. 5, which engage a rounded or cam surface 224 on the bracket. As the bar 27 and racks 251 and 261 are moved lengthwise by the action of the gears 21 or 24, the said bar 27 and attached racks 251 and 261 are slightly raised by the said cam surfaces 252 and 253 to correspond with the amount the pins 33 and 34 rise during their rotation about their centers. This arrangement prevents any binding between the racks and gears which would interfere with the free working of the parts and cause them to wear rapidly and unevenly.

After the door has been opened, the valve 18 and dampers 11 and 12 remain open as long as it is neces sary or convenient, after which the fireman closes the valve and dampers by returning the cranks 20 and 231 to their original positions as shown in Figs. 1 and 2.

I have shown my invention as applied to a furnace having two doors. It is obvious that the invention is also applicable to furnaces having a single door or three doors, modifications in the structure of the device which are necessary to adapt the device to furnaces of other constructions being a matter of mechanical skill only to persons skilled in the art.

I claim as my invention:

1. In a furnace provided with fuel openings, doors for said openings, an air inlet and a steam inlet, the combination of a damper in the air inlet, a valve in the steam inlet provided with a rotatable valve spindle, a gear on the valve spindle, a rack in engagement with the said gear, a slotted connection between the rack and the damper, and

an arm on the said valve spindle for engagement with one of the said doors.

2. In a furnace provided with fuel openings, doors for said openings, an air inlet and a steam inlet, the combination of a valve in the steam inlet, a damper in the air inlet, and operating means for the said valve and damper comprising a rotatable valve spindle, a gear rotatable therewith, and a rack connected to the said damper and engaging the said gear.

3. In a furnace provided with fuel openings, doors for said openings, an air inlet and a steam inlet, the combination of a damper in the air inlet, a valve in the steam inlet, and operating means for said valve and damper, comprising a valve spindle, a crank and gear rotatable therewith, and a rack engaging the said gear and provided with a slotted connection with the said damper.

4. In a furnace provided with fuel-openings, doors for said openings swinging in opposite directions, an air inlet and a steam inlet, the combination of a damper in the air inlet, a valve in the steam inlet, and operating means for said valve and dampers which comprises a valve spindle, a gear and crank for each furnace door, a sliding bar operating said dampers, and racks on opposite sides of the said sliding bar and engaging the said gears.

In testimony whereof I aflix my signature, in presence of two witnesses. I

EDWARD B. PARKHURST.

Witnesses GEORGE P. DIKE, .T. HENRY PARKER. 

